Siemens SENTRON 5SY4140-7KK11 — C-curve MCB for panel protection
The Siemens 5SY4140-7KK11 is a 1-pole miniature circuit breaker from the SENTRON series, designed for branch-circuit and final-subdistribution protection in industrial control panels. Its C-curve tripping characteristic means it holds through moderate inrush — typical for motor-starter and contactor coils, small transformers, and capacitor banks — and trips on sustained overloads at 5–10× rated current. The interrupting capacity is 10 kA per EN 60898-1 and 15 kA per IEC 60947-2, giving headroom for most 400 VAC industrial supply points with fault currents under that threshold. At 18 mm wide, it occupies one modular unit on DIN rail — standard for a single-pole MCB — and mounts in any position. Depth is 76 mm, height 90 mm, with an installation depth of 70 mm. The IP20 rating applies with connected conductors, which is the norm for enclosed panel mounting; no washdown or outdoor exposure is intended.
Standards and compliance
Rated per DIN EN 60898-1 for residential and similar installations, and per IEC 60947-2 for industrial application. The overvoltage category is III, degree of pollution 3, and energy limitation class 3 — meaning it limits let-through energy to a defined level for downstream equipment protection. The design is halogen-free and silicon-free, suitable for environments sensitive to corrosive off-gassing (railway, marine, clean manufacturing). The product designation explicitly notes suitability for railway applications.
Voltage ratings and application range
Rated operating voltage is 400 VAC with a maximum of 440 VAC in single-phase or multi-phase operation. For DC circuits, the rated value is 60 V with a maximum of 72 V. Frequency range is 50/60 Hz. The C-curve and 1-pole design make it a direct fit for single-phase final circuits in distribution boards, motor-control centers, and machine-tool panels where the upstream fault level stays within 10 kA (EN) or 15 kA (IEC).